p1174
Turris

Article by Philip Smith, B.A., of the University of London
on pp1174‑1176 of

TURRIS
(πύργος), a tower. The word τύρσις, from which comes the Latin turris, signified according to Dionysius
(I.26)
any strong building surrounded by walls; and it was from the fact of the Pelasgians in Italy dwelling in such places that the same writer supposes them to have been called Tyrsenians or Tyrrhenians, that is, the inhabitants of towns or castles. Turris in the old Latin language seems to have been equivalent to urbs (Polyb. XXVI.4; Göttling, Gesch. d. Röm. Staatsv. p17). The use of towers by the Greeks and Romans was various.

I. Stationary Towers.

1. Buildings of this form are frequently mentioned by ancient authors, as forming by themselves places of residence and defence. This use of towers was very common in Africa (Diod. Sic. III.49, Itin. Ant. pp34, 35, with Wessling's notes). We have examples in the tower of Hannibal on his estate between Acholla and Thapsus
(Liv. XXXIII.48), the turris
p1175 regia of Jugurtha
(Sallust. Jug. 103), the tower of a private citizen without the walls of Carthage, by the help of which Scipio took the city
(Appian. Pun. 117); and, in Spain, the tower in which Cn. Scipio was burnt
(Appian. Hisp. 16). Such towers were common in the frontier provinces of the Roman empire
(Ammian. Marcell. XXVIII.2).

2. They were erected within cities, partly to form a retreat in case the city should be taken, and partly to overawe the inhabitants. In almost all Greek cities, which were usually built upon a hill, rock, or some natural elevation, there was a kind of tower, a castle, or a citadel, to which the name of
Acropolis
was given, as at Athens, Corinth, Argos, Messene, and many other places. The Capitolium at Rome answered the same purpose as the Acropolis in Greek cities; and of the same kind were the tower of Agathocles at Utica
(Appian. Pun. 14), and that of Antoniaa at Jerusalem (Joseph. Bell. Jud.V.5 §8,
Act. Apostol.XXI.31).

3. The fortifications both of cities and camps were strengthened by towers, which were placed at intervals on the murus of the former [Murus] and the vallum of the latter; and a similar use was made of them in the lines (circumvallatio) drawn round a besieged town. [Vallum.] They were generally used at the gates of towns and of stative camps. [Porta.] The use of temporary towers on walls to repel an attack will be noticed below.

II. Movable Towers. These were among the most important engines used in storming a fortified place. They were of two kinds. Some were made so that they could be taken to pieces and carried to the scene of operations: these were called folding towers (πύργοι πτύκτοι or ἐπτυγμένοι, turres plicatiles, or portable towers, φορητοὶ πυργοὶ). The other sort were constructed on wheels, so as to be driven up to the walls; and hence they were called turres ambulatoriae or subrotatae. But the turres plicatiles were generally made with wheels, so that they were also ambulatoriae.

The first invention or improvement of such towers is described by Athenaeus the mechanician (quoted by Lipsius, Oper. vol. III p297) to the Greeks of Sicily in the time of Dionysius I. (B.C. 405). Diodorus
(XIV.51)
mentions towers on wheels as used by Dionysius at the siege of Motya. He had before
(XIII.54)
mentioned towers as used at the siege of Selinus (B.C. 409), but he does not say that they were on wheels. According to others, they were invented by the engineers in the service of Philip and Alexander, the most famous of whom were Polyidus, a Thessalian, who assisted Philip at the siege of Byzantium, and his pupils Chaereas and Diades
(Vitruv. X.19 s13).
Heron (c13) ascribes their invention to Diades alone, and Athenaeus (l.c.) says that they were improved in the time of Philip at the siege of Byzantium. Vitruvius states that the towers of Diades were carried about by the army in separate pieces. Respecting the towers used by Demetrius Poliorcetes at the siege of Rhodes, see
Helepolis.

Appian mentions the turres plicatiles(Bell. Civ. V.36,
37), and states that at the siege of Rhodes Cassius took such towers with him in his ships, and had them set up on the spot
(Id.IV.72).

Besides the frequent allusions in ancient writers to the moveable towers (turres mobiles,
Liv. XXI.11), we have particular descriptions of them by Vitruvius
(X.19 s13), and Vegetius
(IV.17).

They were generally made of beams and planks, and covered, at least on the three sides which were exposed to the besieged, with iron, not only for protection, but also, according to Josephus, to increase their weight and thus make them steadier. They were also covered with raw hides and quilts, moistened, and sometimes with alum, to protect them from fire. The use of alum for this purpose appears to have originated with Sulla at the siege of Athens (Amm. Marc. XX.
and Claud. Quadrig. ap. Lips. p300). Their height was such as to overtop the walls, towers, and all other fortifications of the besieged place
(Liv. XXI.11). Vitruvius (l.c.), following Diades, mentions two sizes of towers. The smallest ought not, he says, to be less than 60 cubits high, 17 wide, and one-fifth smaller at the top; and the greater 120 cubits high and 23½ wide. Heron (c13), who also follows Diades, agrees with Vitruvius so far, but adds an intermediate size, half-way between the two, 90 cubits high. Vegetius mentions towers of 30, 40, and 50 feet square. They were divided into stories (tabulata or tecta), and hence they are called turres contabulatae
(Liv. XXI.34). Towers of the three sizes just mentioned consisted respectively of 10, 15, and 20 stories. The stories decreased in height from the bottom to the top. Diades and Chaereas, according to Heron, made the lowest story 7 cubits and 12 digits, those about the middle 5 cubits, and the upper 4 cubits and one-third of a cubit.

The sides of the towers were pierced with windows, of which there were several to each story.

These rules were not strictly adhered to in practice. Towers were made of 6 stories, and even fewer
(Diod. XIV.51). Those of 10 stories were very common (Hirt. Bell. Gall.VIII.41; Sil. Ital. XIV.300), but towers of 20 stories are hardly, if ever, mentioned. Plutarch
(Lucull. 10)
speaks of one of •100 cubits high used by Mithridates at the siege of Cyzicus.

The use of the stories was to receive the engines of war [Tormenta], and slingers and archers were stationed on the tops of the towers
(Liv. XXI.11). In the lowest story was a battering-ram [Aries]; and in the middle one or more bridges (pontes) made of beams and planks, and protected at the sides by hurdles. Scaling-ladders (scalae) were also carried in the towers, and when the missiles had cleared the walls, these bridges and ladders enabled the besiegers to rush upon them.

The towers were placed upon wheels (generally 6 or 8), that they might be brought up to the walls. These wheels were placed for security inside of the tower.

The tower was built so far from the besieged place as to be out of the enemy's reach, and then pushed up to the walls by men stationed inside of and behind it (Caesar, B. G.II.30,
31;
Q. Curt. VIII.10). The attempt to draw them forward by beasts of burden was sometimes made, but was easily defeated by shooting the beasts (Procop. Bell. Goth.I. ap. Lips. p298). They were generally brought up upon the
Agger
(Hirtius, l.c.), and it not unfrequently happened that a tower stuck fast or fell over on account of the softness of the agger (Liv. XXXII.17;
Q. Curt. IV.6 §9). They
p1176 were placed on the agger before it was completed, to protect the soldiers in working at it (Sall. Jugurth. 76;
Caesar, B. G.VII.22). When the tower was brought up to the walls without an agger, the ground was levelled before it by means of the
Musculus.

These towers were accounted most formidable engines of attack. They were opposed in the following ways.

1. They were set on fire, either by sallies of the besieged, or by missiles carrying burning matter, or by letting men down from the walls by ropes, close to the towers, while the besiegers slept (Veget. IV.18; Sil. Ital. XIV.305).

2. By undermining the ground over which the tower had to pass, so as to overset it
(Veget. IV.20).

3. By pushing it off by main force by iron-shod beams, asseres or trabes (Veget. l.c.).

4. By breaking or overturning it with stones thrown from catapults, when it was at a distance, or, when it came close to the wall, by striking it with an iron-shod beam hung from a mast on the wall, and thus resembling an Aries.

5. By increasing the height of the wall; first with masonry, and afterwards with beams and planks, and also by the erection of temporary wooden towers on the walls (Caesar, B. G.VII.22;
Veget. IV.19). This mode of defence was answered by the besiegers in two ways. Either the agger on which the tower stood was raised, as by Caesar at the siege of Avaricum (B. G.l.c.), or a smaller tower was constructed within the upper part of the tower, and when completed was raised by screws and ropes (Veget. l.c.). On these towers in general see Lipsius, Poliorc. in Oper. vol. III pp296‑356.

III. Caesar
(B. C. III-8‑9)
describes a peculiar sort of tower, which was invented at the siege of Massilia, and called turris latericia, or laterculum. It partook somewhat of the character both of a fixed and of a besieging tower. It was built of masonry near the walls of the town to afford the besiegers a retreat from the sudden sallies of the enemy; the builders were protected by a moveable cover; and the tower was pierced with windows for shooting out missiles.

IV. Towers in every respect similar to the turres ambulatoriae (excepting of course the wheels) were constructed on ships, for the attack of fortified places by sea (Caes. Bell. Civ.III.40, where, respecting the term ad libram, see the commentators;
Liv. XXIV.34,
Appian. Mith. 73,
Bell. Civ.V.106;
Amm. Marc. XXI.12).

V. Small towers carrying a few armed men were placed on the backs of elephants used in battle
(Liv. XXXVII.40).